Transmitter



Dec. 4, 1934. w KUMMERER 1,982,916

TRANSMITTER Filed Nov. 8, 1930 INVENTOR WILHELM KUMMERER ATTORNEYPatented Dec. 4, 1934 UNITED, STATES TRANSMITTER.

Wilhelm Kummerer, Berlin, Germany, assignor to Telefunken Gesellschaftfiir Drahtlose Telegraphic in. b. H., Berlin, Germany, a corporation ofGermany Application November 8, 1930, Serial No. 494,290v

In Germany November 15, 1929 Claims. (01. 250-36) This invention relatesto an arrangement for eliminating reaction of the master valve upon apilot valve in separately excited valve-transmitter equipment. 5 'InGerman Patent No. 459,005 an arrangement has been disclosed intended toobviate the reaction often produced by the master transmitter valve uponthe pilot tube. For this purpose, a resonant short-circuit link or unitis provided in the output circuit of the frequency-multiplication tubetuned to a harmonic of the fundamental wave, said unit being tuned tothe fundamental wave, i. e., the wave of the pilot valve. In this way,the reaction produced upon the pilot valve inv the presence of antennasway will be minimized. I

Now, according to the present invention the operation of the scheme isimproved by that a tuned short-circuit path is provided not only in 20the output circuit of the mastervalve, but alsoin the grid circuitthereof, it being understood that the short-circuit unit in the gridcircuit must be tuned to the higher harmonic.

One embodiment of the invention is illustrated in the drawing.

0 indicates an oscillation generator having a control electrode 1connected through an inductance 3 to the cathode 5. The anode 9 isconnected in a high frequency output circuit including blockingcondenser C, a unit W having parallel branches 10, 15 and 16, and thecathode 5. Direct current potential is applied to the anode 9 of tube 0through a choking inductance '7. The inductance 10 is coupled to theinductance 3 in the grid cathode circuit of 0 to produce sustainedoscillations at a frequency determined by the elements in the output andinput circuits of O.

The unit 10, 6' is also in the input circuit of 40 tube 2, as shown, andimpresses potential variations at the frequency generated by O on theinput electrodes 11, 13 of tube 2. The unit W has a parallel circuitwhich is tuned to the fundamental frequency, while the capacity 15 andinductance 16 are series resonant at a harmonic so that such harmonic isnot impressed on the input electrodes of tube 2. Anode potential for thetube 2 is supplied through choking inductance 12, as shown. 1 A 50 Inthe output circuit of the frequency-doubler tube 2 the oscillationcircuit 4 consists of a resonant short-circuiting unit 6 in conjunctionwith a condenser 8. The grid oscillation circuit contains thecombination of a resonant (tuned) short-circuiting unit 6' and aninductance 10.

The potentials at the harmonic frequency produced in the frequencydoubler tube 2 are set up across the parallel resonant circuit 4 and areapplied therefrom to the amplifienfrom which they may be impressed on tothe power amplifier and 0;; from thence to the radiating systemn. Thebranch 6 of the circuit 4 tuned to the harmonic frequency is seriesresonant, as pointed out in detail hereinbefore, to the fundamentalfrequency so that potentials at said frequency are short-- 5 5 circuitedand are not applied to the amplifier.

In order to prevent potentials at the harmonic frequency-which appear atthe terminals of the parallel resonant circuit l connected with theanode of the frequency doubler 2, from modulat- 7 ing or affecting-thefundamental frequency, impressed from the oscillation generator 0 by wayof the :circuit W including capacity 15, inductance l0 and inductance16, which areparallel resonant to the fundamental frequency, due tocoupling between said input and output circuits or coupling by way ofthe impedance of the tube 2, means is provided, as describedhereinbefore, in the input circuit of 2V to short circuitthe potentialsat the harmonic frequency. This means is, as pointed out in detail Ihereinbefore, the series resonant circuit 15, 16. This circuit, beingseries resonant to the harmonic frequency in the output circuit of 2,acts as a short circuit thereto and therefore no potential differenceappears between the control grid 11 and cathode 13 of the frequencydoubler representative of the harmonic potentials.

I claim:

1. A frequency multiplier comprising an elec- 0;; tron discharge devicehaving an input circuit tuned to a fundamental frequency and an outputcircuit tuned to a frequency harmonically related to the fundamental,said input circuit having parallel branches, one of which includes areactor and the other of which includes inductive and capacitiveelements in series circuit tuned to resonance at the harmonic frequencyand said output circuit comprising two parallel branches, one of whichincludes a reactor and the other of which includes a series circuittuned to series resonance at the fundamental frequency.

2. A frequency developing system comprising an electron discharge devicehaving an input circuit tuned to a fundamental frequency and an outputcircuit tuned to a frequency harmonically related to the fundamental,said input circuit comprising two parallel branches, one of whichincludes a reactor and the other of which includes inductive andcapacitive elements in a series cir- 110,

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cuit tuned to resonance at impedance to energy of the harmonic frequencyand said output circuit comprising two parallel branches, one of whichincludes a capacitor and the other of which includes a series circuittuned to resonance at the fundamental frequency thereby offeringpractically zero impedance to energy of the fundamental frequency.

3. A frequency multiplier comprising, an electron discharge devicehaving anode, cathode and control grid electrodes, an input circuitconnected act as a short circuit for said fundamental frequency, andmeans for preventing oscillations at the harmonic frequency appearingacross the output electrodes of said frequency multiplier from beingapplied tothe input electrodes of said frequency multiplier comprisingreactances in one branch of said input circuit to tune said branch toseries resonance at the harmonic frequency.

4. A frequency multiplier comprising, an electron discharge devicehaving anode, cathode and control grid electrodes, an input circuitconnected between said cathode and grid electrodes, said circuitincluding parallel branches tuned to the fundamental frequency which isto be applied to said input electrodes, an output circuit connectedbetween the output electrodes of said tube, said quency from being setup across said output circuit comprising, capacitive and inductivereact- *multiplier comprising capacitive and inductive reactances in onebranch of said input circuit to tune said branch to series resonance atthe harmonic frequency;

5. A signalling device comprising, a source of highfrequencyoscillations and a load circuit, and means for increasing the frequencyof oscillations fromsaid source and applying the increased frequencyoscillations to said load circuit comprising, a thermionic tube havingits control grid and cathode connected with said source and its anodeelectrodes connected with said load circuit, a circuit comprising aninductance in parallel with a series capacity and inductance connectedbetween the control grid and cathode of said tube, said circuit beingtuned by said inductances and said capacity to parallel resonance at thefrequency of said source, a circuit comprising a capacity and a capacityand inductance" in parallel with said capacity connected between theanode and cathode'electrodes of said thermionic tube, said last namedcircuit being tuned by said capacities and said inductance therein toparallel resonance at a frequency which is a harmonic of the frequencyof said source, the capacity and inductance in one branch of said lastnamed parallel resonant circuit being series resonant at the fundamentalfrequency to provide a short circuit path for the fundamental frequencybetween said output electrodes, the capacitive and inductive branch insaid first named parallel resonant circuit connected between said inputelectrodes being series resonant to the harmonic frequency to provide ashort circuit path between said control grid and said cathode for saidharmonic frequency.

WILHELM KUMMERER.

